<?php
/**
 * Skyline :: Patterns & component framework
 * Copyright 2010-2011 Ian Unruh (Xerof3ar)
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
namespace Skyline\Comparator;

/**
 * 
 * 
 * @author Ian Unruh (Xerof3ar) <ianunruh@gmail.com>
 * @since Class avaliable since release 1.0
 */
class ValueBoundComparator extends DecoratedComparator
{
	/**
	 * @var string
	 */
	protected $propertyName;
	
	/**
	 * Class constructor
	 * 
	 * @param string $propertyName
	 * @param ComparatorInterface $comparator [optional]
	 * @return void
	 */
	public function __construct($propertyName, ComparatorInterface $comparator = null)
	{
		parent::__construct(($comparator ?: new NaturalComparator()));
		$this->propertyName = $propertyName;
	}
	
	/**
	 * Compares a left value to a right value and returns an integer comparison
	 * 
	 * @param mixed $left
	 * @param mixed $right
	 * @return int (-1 = less than, 0 = equal, 1 = greater than)
	 */
	public function compare($left, $right)
	{
		$methodName = 'get' . ucfirst($this->propertyName);
		
		$left = $left->$methodName();
		$right = $right->$methodName();
		
		return $this->comparator->compare($left, $right);
	}
	
	/**
	 * Returns the name of the property being compared
	 * @return string
	 */
	public function getPropertyName()
	{
		return $this->propertyName;
	}
}